Estes Altimeter, Holes

[neil_w]

Good point(s)!

 

[icyclops]

I'm worried that you're all creating a solution for a nonexistent problem. Just poke a few evenly spaced holes (visually hide them if desired, but don't alter/block aerodynamically). Been done this way for quite some time without issue.
-Ken

Ken, you are probably correct…but if you are making your holes big or highly visible for MP or otherwise, then it can be kind of ugly too…so if you can turn them into a design element then it could be a win-win. But you are right, just punch a hole.

 

[new2hpr]

Vent hole size (for barometric altimeters) is not dependent at all on LPR, MPR, HPR, only the recommendation of the altimeter manufacturer. It just needs to be enough to equalize pressure between inside and outside. Assuming that's what you meant by MP?
-Ken

 

[neil_w]

Vent hole size (for barometric altimeters) is not dependent at all on LPR, MPR, HPR, only the recommendation of the altimeter manufacturer. It just needs to be enough to equalize pressure between inside and outside. Assuming that's what you meant by MP?
-Ken

It's primarily determined by the volume of the compartment that holds the altimeter. The larger the compartment, the larger the holes you need to allow the pressure to equalize quickly. Altimeter manufacturers should be expected to provide similar (if not necessarily exactly the same).

In LPR it's often enough to just use pinholes. Much larger rockets (e.g. HPR) will often require larger holes. So size is *correlated* with LPR/MPR/HPR, but the power of the motor has nothing to do with it.

 

[cerving]

Most rockets are pretty leaky, and with an apogee-only altimeter you really only need the ground and apogee readings. If you're really worried about it, poke a very small hole into wherever your altimeter is, but I would be willing to bet that it won't really make a difference.

 

[Joekeyo]

Can you put holes in the main BT? Does it vent the ejection charge?

 

[waltr]

Can you put holes in the main BT? Does it vent the ejection charge?

I put vent holes in main BT of large rockets to allow pressure equalizing so the Nose does not get 'pushed off' at altitude. Does not effect ejection.